Effect of current regulation on Wigner energy release rate during induction annealing of irradiated nuclear graphite

摘要: Wigner energy release during induction annealing of irradiated nuclear graphite changes the temperature history and the coil current required for temperature tracking. A nonnegative independent parallel reactions model with 20 nodes is coupled with the induction electromagnetic field, transient heat transfer, and feedback based on mean temperature. Cases using a prescribed current program and feedback current reduction are compared, and target heating rates are scanned. Relative to the prescribed current case W1, feedback case W2 reduces the sampled peak Wigner heat release power from 8.803 to 4.708 kW, a 46.5% reduction. The sampled peak is delayed from 1680 to 1800 s. Feedback delays early stored energy release, but both cases release more than 99.6% of their initial stored energy by the program endpoint. The power curves cross near the main peak, indicating temporal redistribution rather than a reduction in instantaneous heat release power at every stage. After the W2 current reaches zero, the mean heating rate over 1920-1980 s remains 7.78 K/min, exceeding the 5 K/min target.Matched cases without heat release further show that coupling of the Wigner heat source reduces the margin for current reduction in Reach. Under the specified material, thermal boundary, and control conditions, current feedback regulates Wigner heat release by changing temperature histories and stored energy depletion. Annealing programs should be assessed using peak Wigner heat release power, cumulative release fraction, and the zero-current constraint.